Lead for the temporary stimulation of a peripheral nerve

ABSTRACT

Apparatus and associated methods relate to a lead that includes metallic traces sandwiched between layers of polymers to form a ribbon (e.g., similar to a flex circuit). In an illustrative example, areas on both ends of the traces may be exposed, forming stimulation electrodes on one end and electrical contacts on the other. The ribbon may be formed such that it fits down a small diameter needle. When the needle is removed, the formed ribbon may relax and engage the tissue providing a means of retention. The lead may advantageously: (1) be minimally invasive to implant, (2) be inexpensive, (3) stay in place a temporary/trial medical procedure setting, and (4) be easy to remove.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application also claims the benefit of U.S. Provisional ApplicationSer. No. 62/839,357, titled “Lead for the temporary stimulation of aperipheral nerve,” filed by John Swoyer, et al., on Apr. 26, 2019.

This application incorporates the entire contents of the foregoingapplication(s) herein by reference.

TECHNICAL FIELD

Various embodiments relate generally to design of a temporaryneurostimulation lead.

BACKGROUND

There are a variety of therapies that involve the stimulation ofperipheral nerves for the treatment of disease states. Some of thesetherapies may be chronic, and others may be acute. For example, sacralnerve stimulation may be an example of chronic stimulation of a nervefor the treatment of overactive bladder and other disorders of thepelvic area. Stimulation of nerves near a joint or muscle may be usedfor temporary relief of acute pain, while a chronic implant may be usedfor long-term pain.

SUMMARY

Apparatus and associated methods relate to a lead that includes metallictraces sandwiched between layers of polymers to form a ribbon (e.g.,similar to a flex circuit). In an illustrative example, areas on bothends of the traces may be exposed, forming stimulation electrodes on oneend and electrical contacts on the other. The ribbon may be formed suchthat it fits down a small diameter needle. When the needle is removed,the formed ribbon may relax and engage the tissue providing a means ofretention. The lead may advantageously: (1) be minimally invasive toimplant, (2) be inexpensive, (3) stay in place in a temporary/trialmedical procedure setting, and (4) be easy to remove.

Additional uses include stimulation of cranial nerves, included but notlimited to the Vagus nerves to treat conditions, including but notlimited to, depression or insomnia. The details of various embodimentsare set forth in the accompanying drawings and the description below.Other features and advantages will be apparent from the description anddrawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1, 1A, 1B, and 1C depict various top perspective views of anexemplary lead ribbon including two traces with exposed ends.

FIG. 2 depicts a perspective view of an exemplary lead, with zoomed indetail on the distal end of the lead illustrating exposed electrodes.

FIG. 3 depicts a perspective view of an exemplary lead, with zoomed indetail on the distal end of the lead illustrating fixation members.

FIGS. 4A, 4B, and 4C depict perspective views of an exemplary leadribbon installed in a needle with a stylet.

FIGS. 5A and 5B depict cross-sectional views (longitudinal and lateralcross sections) of an exemplary needle, stylet, and lead assembly.

FIG. 6 depicts a perspective view of an exemplary ribbon lead wrappedaround an exemplary stylet.

FIG. 7 depicts a perspective view of a distal end of an exemplary leadand stylet assembly.

FIG. 8 depicts a perspective view of an exemplary lead embedded insidetissue.

FIG. 9 depicts a side elevation view of an exemplary ribbon wrappedaround a stepped stylet to form an inner wrap and an outer wrap.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Not all patients respond to stimulation treatments. Therefore, in somesituations, it may be desirable to have a trial stimulation todemonstrate efficacy prior to an expensive and invasive procedure toimplant a chronic system. To be useful, a temporary/trial procedure mayuse a lead that is minimally invasive to implant, in a setting such as adoctor's office, be inexpensive, stay in place during the trial, and beeasy to remove. Accordingly, disclosed herein is a lead designed to meetthe above described requirements.

FIGS. 1, 1A, 1B, and 1C depict various top perspective views of anexemplary lead ribbon including two traces with exposed ends. Thesefigures show the lead ribbon 100 (with exemplary dimensions) having twotraces 115, 120 with exposed ends. FIG. 1A illustrates finer detail ofthe proximal end 105 of the straight lead ribbon 100 (detail A shown inFIG. 1), while FIG. 1B illustrates the same detail as FIG. 1A but withthe top layer of insulation removed to reveal more of the traces.

FIG. 1C illustrates finer detail of the distal end 110 of the leadribbon 100 (detail B shown in FIG. 1). The traces 115, 120 may becovered with insulation 125 (e.g., polyimide), with one side of each endexposed. The distal end 110 may be configured as electrodes (e.g., apair of pads), with the proximal exposed end 105 used to connect to anelectrical stimulator, or a cable that then connects to a stimulator,for example. It is understood that any number, shape or size of traces,electrodes, and connections could be formed in this manner.

FIG. 2 depicts a perspective view of an exemplary lead, with zoomed indetail on the distal end of the lead illustrating exposed electrodes.This figure shows a close up of the distal end 110, revealing the twoexposed electrodes.

FIG. 3 depicts a perspective view of an exemplary lead, with zoomed indetail on the distal end of the lead illustrating fixation members. Insome embodiments, the distal end 110 with optional fixationfeatures/members 130. The fixation members 130 may be formed as multipleteeth, each having a triangular profile, for example. The members 130may be designed such that they add facilitate additional engagement withsurrounding tissue. It is understood that a variety of shapes and sizescould be used, and the features could be located anywhere along the leadribbon.

FIGS. 4A, 4B, and 4C depict perspective views of an exemplary leadribbon installed in a needle with a stylet. A stylet 135 is inserted ina (hollow) needle 140, with a lead ribbon 100 residing inside of theneedle 140. The lead ribbon is installed in the needle with the stylet.

FIGS. 5A and 5B depict cross-sectional views (longitudinal and lateralcross sections) of an exemplary needle, stylet, and lead assembly. Thelongitudinal and lateral cross section of the assembly reveals the leadribbon 100 wrapped around the stylet 135 within the needle 140, preparedfor insertion into the patient.

FIG. 6 depicts a perspective view of an exemplary ribbon lead wrappedaround an exemplary stylet. After insertion into a patient near thestimulation target, the needle 140 may be withdrawn, as shown in FIG. 6.

FIG. 7 depicts a perspective view of a distal end of an exemplary leadand stylet assembly. This illustration shows a detailed view with theneedle removed (traces and fixation features are not shown for clarity).In some examples, the stylet may advance to push the lead out of thetip, which may allow the lead to spring open and catch the surroundingtissue. Then the stylet may be slid out, and then the needle slid outover the lead.

FIG. 8 depicts a perspective view of an exemplary lead embedded insidetissue. Once the needle is removed, and the stylet withdrawn, the spiralwound ribbon 100 will tend to expand radially, engaging the tissue asshown in FIG. 8. The (optional) fixation members/features (not shown)may provide additional engagement with the surrounding tissue. Thespiral form of the ribbon may allow some stretch of the lead as thepatient moves, minimizing the chance of dislodgement. When it is time toremove the lead, the proximal end of the ribbon can be grasped andpulled. This may cause the ribbon to unwind and easily come out of thepatient.

FIG. 9 depicts a side elevation view of an exemplary ribbon wrappedaround a stepped stylet to form an inner wrap and an outer wrap. As seenin FIG. 9, a ribbon 100′ is featured that is wrapped more than 360degrees around a stylet 135′. The stylet 135′ includes an area providinga step or shoulder 135A′ for the stylet 135 to push against the ribbon100′. The ribbon 100′ is wrapped greater than 360 degrees, such that theribbon 100′ forms an inner ribbon wrap 100A′ and an outer ribbon wrap100B′. The step/shoulder 135′ on the stylet 135′ engages a step formedbetween the inner and outer wraps 100A′, 100B′, which advantageouslyaids in pushing the ribbon 100′ out of the tube (not shown).

Although various embodiments have been described with reference to theFigures, other embodiments are possible. In various examples, a lead fortemporary stimulation of a peripheral nerve includes a lead ribbon. Thelead ribbon may include a lead ribbon substrate. The lead ribbon mayinclude at least one trace running along a length of the lead ribbonsubstrate between a lead ribbon proximal end to a lead ribbon distalend. The lead ribbon may include a pair of electrodes located at thelead ribbon distal end and in electrical communication with the at leastone trace, respectively. The lead ribbon may include at least oneexposed electrical stimulation pad located at the lead ribbon proximalend and in electrical communication with the at least one trace. Thelead for temporary stimulation of a peripheral nerve may include astylet. The lead ribbon may be wrapped around the stylet such that anexposed surface of the at least one electrical stimulation pad isoriented radially outward relative to the stylet.

The lead for temporary stimulation of a peripheral nerve may include ahollow needle in which the lead ribbon wrapped around the styletresides. The at least one trace may be enclosed by electricalinsulation, the electrical insulation extending between the lead ribbonproximal end to the lead ribbon distal end. The lead ribbon may behelically wrapped around the stylet. The lead ribbon may includemultiple fixation features disposed along the length of the lead ribbonand configured to fixingly engage with surrounding patient tissue. Themultiple fixation features include a plurality of teeth located onopposing lateral sides of the lead ribbon. The lead ribbon may include aspringing lead ribbon configured to spring open and catch surroundingpatient tissue after the lead ribbon is released from the stylet insidea patient. After the lead ribbon is released from the stylet inside thepatient, the lead ribbon may be configured to expand radially toretainingly engaging surrounding patient tissue. The lead ribbon may bestretchable along a longitudinal axis defined by the stylet. In someembodiments, the at least one trace may include a pair of traces, the atleast one electrode trace may include a pair of electrode, and the atleast one exposed electrical stimulation pad trace may include a pair ofexposed electrical stimulation pads, the pair of electrodes may be inelectrical communication with the pair of traces, respectively, and thepair of exposed electrical stimulation pads may be in electricalcommunication with the pair of traces, respectively. In someembodiments, the stylet may include a stepped stylet. In someembodiments, the lead ribbon may be configured to wrap around the styletmore than 360 degrees to form an inner ribbon wrap and an outer ribbonwrap.

A method for the insertion of a lead for temporary stimulation of aperipheral nerve may include inserting into an electrical stimulationassembly into a patient proximate to a stimulation target. Theelectrical stimulation assembly may include a lead ribbon. The leadribbon may include a lead ribbon substrate, at least one trace runningalong a length of the lead ribbon substrate between a lead ribbonproximal end to a lead ribbon distal end, at least one electrodedisposed at the lead ribbon distal end and in electrical communicationwith the at least one trace, respectively, and at least one exposedelectrical stimulation pads disposed at the lead ribbon proximal end andin electrical communication with the at least one trace, respectively.The electrical stimulation assembly may include a stylet, where the leadribbon may be helically wrapped around the stylet such that an exposedsurface of the at least one electrical stimulation pad is orientedradially outward relative to the stylet. The electrical stimulationassembly may include a hollow needle in which the lead ribbon wrappedaround the stylet resides. The method may include advancing the styletto push the stylet out of a tip of the hollow needle to effectuatespringing open of the lead ribbon to catch surrounding tissue. Themethod may include sliding the stylet out from the surrounding tissueand separating the stylet from the lead ribbon and hollow needle. Themethod may include sliding the hollow needle out from the surroundingtissue and separating the hollow needle from the lead ribbon. The methodmay include expanding the helically oriented lead ribbon radiallyoutward to engage the surrounding tissue.

In some embodiments, the at least one trace may include a pair oftraces, the at least one electrode may include a pair of electrodes, andthe at least one exposed electrical stimulation pad may include a pairof exposed electrical stimulation pads, the pair of electrodes may be inelectrical communication with the pair of traces, respectively, and thepair of exposed electrical stimulation pads may be in electricalcommunication with the pair of traces, respectively. In variousimplementations, the proximal pads may not be exposed, with connectionmade via an insulation displacement connector. In such an implementationthere would not even need to be a specific pad (per se), and connectioncould be made to the trace. In such implementations, the lead could becut off to be made shorter, if so desired.

A number of implementations have been described. Nevertheless, it willbe understood that various modification may be made. For example,advantageous results may be achieved if the steps of the disclosedtechniques were performed in a different sequence, or if components ofthe disclosed systems were combined in a different manner, or if thecomponents were supplemented with other components. Accordingly, otherimplementations are within the scope of the following claims.

What is claimed is:
 1. A lead for temporary stimulation of a peripheralnerve, the lead comprising: a lead ribbon comprising: a substantiallyflat lead ribbon substrate extending substantially in a first plane whenin an unwound state; at least one trace running along a length of thelead ribbon substrate between a lead ribbon proximal end to a leadribbon distal end; at least one electrode disposed at the lead ribbondistal end and in electrical communication with the at least one trace;at least one exposed electrical stimulation pad disposed at the leadribbon proximal end and in electrical communication with the at leastone trace; and, a plurality of fixation features extending in the firstplane form at least a first edge of the lead ribbon substrate when thelead ribbon substrate is in the unwound state; and, a stylet, whereinthe lead ribbon is wrapped around the stylet such that an exposedsurface of the at least one electrical stimulation pad is orientedradially outward relative to the stylet, wherein, when the lead ribbonis deployed from the stylet within a lumen in tissue such that theplurality of fixation features engage the tissue and the lead ribbonproximal end is pulled, then the lead ribbon unwinds such that theplurality of fixation features disengage from the tissue.
 2. The lead ofclaim 1, further comprising a hollow needle in which the lead ribbonwrapped around the stylet resides.
 3. The lead of claim 1, wherein theat least one trace is enclosed by electrical insulation, the electricalinsulation extending between the lead ribbon proximal end to the leadribbon distal end.
 4. The lead of claim 1, wherein the at least onetrace comprises a pair of traces, the at least one electrode comprises apair of electrodes, and the at least one exposed electrical stimulationpad comprises a pair of exposed electrical stimulation pads, and thepair of electrodes are in electrical communication with the pair oftraces, respectively, and the pair of exposed electrical stimulationpads are in electrical communication with the pair of traces,respectively.
 5. The lead of claim 1, wherein the lead ribbon ishelically wrapped around the stylet.
 6. The lead of claim 1, wherein theplurality of fixation features comprise a plurality of teeth disposed onopposing lateral sides of the lead ribbon.
 7. The lead of claim 1,wherein the lead ribbon comprises a springing lead ribbon configured tospring open and catch surrounding patient tissue after the lead ribbonis released from the stylet inside a patient.
 8. The lead of claim 7,wherein after the lead ribbon is released from the stylet inside thepatient, the lead ribbon is configured to expand radially to retaininglyengaging surrounding patient tissue.
 9. The lead of claim 7, wherein thelead ribbon is stretchable along a longitudinal axis defined by thestylet.
 10. The lead of claim 1, wherein the stylet comprises a steppedstylet.
 11. The lead of claim 1, wherein the lead ribbon is configuredto wrap around the stylet more than 360 degrees to form an inner ribbonwrap and an outer ribbon wrap.
 12. A method for insertion of a lead fortemporary stimulation of a peripheral nerve, the method comprising:inserting into an electrical stimulation assembly into a patientproximate to a stimulation target, wherein the electrical stimulationassembly comprises: a lead ribbon comprising: a substantially flat leadribbon substrate extending in a first plane when in an unwound state; atleast one trace running along a length of the lead ribbon substratebetween a lead ribbon proximal end to a lead ribbon distal end; at leastone electrode disposed at the lead ribbon distal end and in electricalcommunication with the at least one trace; at least one exposedelectrical stimulation pad disposed at the lead ribbon proximal end andin electrical communication with the at least one trace; and, aplurality of fixation members extending in the first plane form at leasta first edge of the lead ribbon substrate when the lead ribbon substrateis in the unwound state; and, a stylet, wherein the lead ribbon iswrapped around the stylet such that an exposed surface of at least oneelectrical stimulation pad is oriented radially outward relative to thestylet; and, a hollow needle in which the lead ribbon wrapped around thestylet resides; advancing the stylet to push the stylet out of a tip ofthe hollow needle to effectuate springing open of the lead ribbon tocatch surrounding tissue, sliding the stylet out from the surroundingtissue and separating the stylet from the lead ribbon and hollow needle,sliding the hollow needle out from the surrounding tissue and separatingthe hollow needle from the lead ribbon, expanding the lead ribbonradially outward such that the plurality of fixation members engage thesurrounding tissue, and, pulling the lead ribbon proximal end to unwindthe lead ribbon such that the plurality of fixation members disengagefrom the tissue.
 13. The method of claim 12, wherein the at least onetrace comprises a pair of traces, the at least one electrode comprises apair of electrodes, and the at least one exposed electrical stimulationpad comprises a pair of exposed electrical stimulation pads, and thepair of electrodes are in electrical communication with the pair oftraces, respectively, and the pair of exposed electrical stimulationpads are in electrical communication with the pair of traces,respectively.
 14. The method of claim 13, wherein the pair of traces areenclosed by electrical insulation, the electrical insulation extendingbetween the lead ribbon proximal end to the lead ribbon distal end. 15.The method of claim 12, wherein the lead ribbon comprises a springinglead ribbon configured to spring open and catch surrounding patienttissue after the lead ribbon is released from the stylet inside apatient.
 16. The method of claim 12, wherein after the lead ribbon isreleased from the stylet inside the patient, the lead ribbon isconfigured to expand radially to retainingly engaging surroundingpatient tissue.
 17. The method of claim 12, wherein the lead ribbon isstretchable along a longitudinal axis defined by the stylet.
 18. Themethod of claim 12, wherein the lead ribbon is helically oriented whenwrapped around the stylet.
 19. A lead for temporary stimulation of aperipheral nerve, the lead comprising: a lead ribbon comprising: asubstantially flat lead ribbon substrate extending in a first plane whenin an unwound state; a pair of traces running along a length of the leadribbon substrate between a lead ribbon proximal end to a lead ribbondistal end; a pair of electrodes disposed at the lead ribbon distal endand in electrical communication with the pair of traces, respectively;and, a pair of exposed electrical stimulation pads disposed at the leadribbon proximal end and in electrical communication with the pair oftraces, respectively; a stylet, wherein the lead ribbon is wrappedaround the stylet such that an exposed surface of each of the pair ofelectrical stimulation pads are oriented radially outward relative tothe stylet; and, a plurality of means for fixation extending in thefirst plane from at least a first edge of the lead ribbon substrate whenthe lead ribbon substrate is in the unwound state and disposed along thelength of the lead ribbon and configured to fixingly engage withsurrounding patient tissue, the plurality of means for fixation furtherconfigured to disengage from the tissue when the lead ribbon proximalend is pulled.
 20. The lead of claim 19, the lead ribbon furtherconfigured such that, when the lead ribbon proximal end is pulled, thelead ribbon unwinds such that the plurality of means for fixationdisengage from the tissue.